Of course, I know they mean "low kinetic energy" and not "low total energy," but in that case they could have just said "low airspeed" with no loss of information. But no, they have to muddy the waters by using the fancy high tech sounding term. Unqualified "energy" is supposed to mean "total energy
Actually they are correct, the
total energy decreases under the work of the increased drag, since the initial total energy+work of drag force(-)=final total energy(lower). They say you have to increase Power(thrust force) to recover the lost of kinetic energy(and to recover the initial total energy) in order to keep the flight path. Otherwise, by keeping the lower total energy state you have to trade your potential energy towards the kinetic energy, before the alfa floor kicks in.